1. Technical Field
The present invention relates to a printing device, a control method of a printing device, and a program.
2. Related Art
Label printers that use roll paper having labels affixed at a regular interval to a continuous liner, and print on labels of the roller label paper, are known from the literature. Such label printers convey each label to a printing position for printing, peel the label from the liner with a peeler (a label separating mechanism), and then discharge the printed labels from a label exit.
If a printed label is not correctly peeled from the liner, or if the label discharged from the label exit is not removed by the user, conveyance problems may result from the liner being conveyed with the label still attached, or the label sticking in the label exit and causing a paper jam.
A detector may therefore be disposed on the downstream side of the printing position to detect if each label is correctly peeled or if the label was removed from the label exit.
Such label detectors are, however, normally located on the upstream side of the label exit, and when a photodetection unit is used as the detector, light noise from outside the label exit can cause detection errors.
JP-A-H09-249339 discloses technology for detecting whether paper is present in a printer having an optical sensor including an emitter and a detector. The printer detects the output level of the detector when the emitter is not emitting, adds a predetermined specific value to this detection level to set a threshold value, detects the output level of the detector when the emitter is emitting, and compares this detection level with the threshold value to determine if media is present.
The technology described in JP-A-H09-249339 acquires a detection result from which the effect of external light noise has been removed. However, because the effect of the external environment changes continuously due to aging and changes in the position or ambient environment of the label printer, appropriately detecting whether a label is present may not be possible depending on the actual operating environment where the label printer is used.